Safety device.



C. F. ROOT.

SAFETY DEVICE.

APPLICATION FILED AUG-30. I915.

1 ,Qflfifi l Patented Oct. 24, 1916.

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C. F. ROOT.

SAFETY DEVICE.

APPLICATION FILED AUG.30. 1915.

LQUQAM, Patented 00. 24,1916.

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C. F. ROOT.

SAFETY DEVICE.

APPLICATION FILED Aue.ao. i915.

Patented Oct. 24, 1916.

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C. F. ROOT.

SAFETY DEVICE.

APPLICATION FILED AUG.30. 1915.

LUAM, Patented Oct. 24,1916.

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SAFETY DEVICE.

APPLICATION FILED AUG.30. 1915.

IQQQL-QEJL. Patented Oct. 24,1916.

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CHARLES E. ROOT, OF RAVENNA, OHIO, ASSIGNOR OF ONE-FOURTH TO BYRON O. CONN,

OF MANSFIELD, OHIO.

SAFETY DEVICE.

Specification of Letters Patent.

Patented Oct. 2a, 1916.

Application filed August 30, 1915. Serial No. 48,014.

To all whom it may concern:

Be it known that I, CHAnLEs F. ROOT, a citizen of the United States of America, residing at llavenna, in the county of Portage and State of Ohio, have invented certain new and useful Improvements in Safety Devices, of which the following is a specification.

This invention relates to safety devices for machines equipped with a moving ele ment and an opposing element which are adapted to act and exert a pressure upon work interposed between said elements, the specific construction of the present inven tion being more particularly applicable for use in connection with the conventional type of job printing presses.

It is well known that the operation of machines of the class described is highly dangerous to the operators thereof because by reason of inadvertence, accident, mistake or otherwise the operators fail to remove from between or interpose. the hands or fingers between the elements and they are caught between the elements, injured, maimed and crushed by the pressure of the elements exerted thereon.

It is further well known that in the operation of machines having a moving or reciprocating element and an opposing element such as printing presses, punch presses, staying machines and the like, that the operator must place the hands or fingers between the elements many times in the course of a days operation for the purpose of placing therebetween work to be acted upon by the elements.

To operate machines of the class described for performing the work for which they are adapted, economically, efficiently and to their maximum capacity, they must be run or speeded up so as to leave just sufiicient ime for the operator to remove from and place the work between the work engaging element. It is desirable therefore to provide automatic means operable by contact with the hands or fingers of the operator to prevent injury thereto which is operable in stantly without the exercise of any'mental or physical effort upon the 'part of the ope ator.

As the capacity or speed of the machine is increased, the liability or danger of the operator of being injured is increased as the operator must interpose his hands or fingers between the work engaging elements oftener and the period of time is shortened in which the operator must place the work between and remove his hands and fingers from between the work engaging elements, it is therefore of the utmost importance in the matter of safety of the operator and the capacity ofthe machine that the safety operating mechanism shall be automatically operable without any physical or mental efi'ort upon the part of the operator in the event of his hands or fingers being caught between the elements, such mechanism permitting the operator to speed up the machine to correspond with the ability of the operator to handle the work without fear of being injured. I

The primary object of this invention is to provide controlling means for automatically controlling, and restricting the movement of the movable work engaging element operable upon contact of the controlling means with the fingers or hands of the operator and so locating, arranging and 0011- structing the controlling means that when the operator fails to remove his hands or fingers from between the elements or by inadvertence, accident or mistake or otherwise the operators hands or fingers are interposed between the elements, that the controlling ,means will first contact with the fingers or hands of the operator thereby actuating the safety mechanism to prevent the work engaging element from completing its working movement in the direction of the opposing element leaving a predetermined gap between the elements of suflicient width to permit the hand or fingers to remain therebetween without danger of injury.

Another object is to provide a safety mechanism that can be manipulated by hand periodically at the. will of the operator to prevent the work engaging element from exerting a pressure upon the work and to continuously maintain said work engaging element inoperative if desired, thereby combining .a safety mechanism with what is designated in the printers art as a throwoff mechanism.

A further object is to provide means of interlocking the driving means to the work engaging element for movement in unison and means to actuate the driving means to ance jar, vibration, pounding or hammering of the parts due to the gravity thereof or because of the actuation of the parts for they purpose intended.

The above described objects are set out in my application hearing date of Aug. 2, 1915, Serial of 1915, No. 43,149 and the same objects are common and generic to the present invention.

The present and invention describes claims a different means of accomplishing the above described objects and the preferable specific means comprise combined links and cams which are pivotally connected to the driving links and rigidly connected to the cross. connecting shaft of the work engaging element forming knee joints between the work engaging element and the driving links, to provide means of forcing thework engaging element to travel to the end or its working stroke under normal conditions and which is also operated to prevent it from traveling to the end of its working stroke when the controller which is operated to release suitable mechanism to permit it to connect with and impart movement to the combined toggle links and cams when the controller is subjected to pressure.

A further object is to provide a mechanism that is automatically operable by a controller to impart movement to an unlocking member, and simultaneously and in conjunction therewith a pivotal movement to the combined cam toggle links when the controller subjected to pressure or resist- (e' e. contacts with the hands or fingers of the operator as shown in Fig. 3; said mechanism being normally inoperable to impart movement to the unlocking member and combined cam toggle links.

Another object is to pivotally mount the controller upon the cross connecting shaft of the work engaging element and to pro vide means of normally retaining it in a predetermined position in the path of and between the work engaging elements, the contact portion of the controller being preferably arranged to swing toward and in close proximity to the top of the movable work engaging elements when it meets with I an. obstruction, resistance or is subjected to pressure.

A further object of this invention is to provide means of operating an unlocking member and to maintain it in operation until suitable connecting mechanism is actu ated by resistance or pressure upon the controller to automatically impart movement to said unlocking member which in turn iInbetween the driving means and the work engaging element, thereby preventing the work engaging element from traveling to the'end of its working movement.

vThis invention further consists in the utilization of an arm carried by the crank pin of the disk which contacts with a cam which under abnormal conditions is adapted to be connected to a movable unlocking member which forces the combined cam toggle links to break their connections with the driving means and throw thorn off their dead center positions when the controller meets resistance or is subjected to pressure, thereby preventing the work engaging element from completing its working movement, a contiguous portion of said cam also being adapted in connection with said arm to return the sliding connecting mechanism of the unlocking member to its connecting position upon every idle movement of the Work engaging element.

A further object of this invention is to combine a safety device and a throw-off mechanism in a single mechanism.

Another feature of the present invention consists in its ready and easy adaptability and attachment to job presses or the like now in use without any alteration or change thereof. the safety and throw-off mechanism being mounted upon the driving means and the controller upon the connecting cross shaft of the movable work engaging element.

This invention consists briefly in the following instrumentalities: a removable and attachable driving means connected to the movable work engaging element to provide a knee joint; means to break the joint which is aiiitomatically operated when the controlling mechanism is actuated by resistance or pressure upon the controller; means to maintain the knee joint in locked position under normal conditions, and means to actuate the knee joint mechanism to force it to locked or normal position after the knee joint has been broken because of resistance or pressure upon the controller which automatically actuates the connecting mechanism of the knee oint breaking it or throwing it err dead center position.

The distinguishing characteristics of the present invention preferably comprise a ciprocating movement to the sliding ratchet bar w iich in turn is automatically connected to the unlocking member by a bell crank pawl when the controller is resisted or subjected to pressure by means of which the movement of the movable work engaging element is controlled to leave a predeten mined safety zone between the work engaging element.

Another object of this invention is to provide a safety and throw-off mechanism that is operable by pressure upon a controller, the mechanism actuated by the controller being so arranged, constructed and combined that when the mechanism is actuated to throw off the in'ipression or to provide a safety zone between the work engaging ele ments, said mechanism will always be connected to the movable work engaging element in such a manner as to gradually stop the movement thereof in the direction of the opposing element but because of being continuously connected to said mechanism, the play of all of the parts will be automatically taken up and the parts so controlled and governed that all vibration, pounding and jarring of the parts incident to changing the travel of the work engaging element is eliminated.

These and other objects are attained by the mechanism illustrated in the accompanying drawing, in which:

Figure 1 is a side elevation of a conventional type of job press showing the combined safety and throw-off mechanism applied thereto, also showing the position of the parts thereof when the movable work engaging element is at the end of its idle movement or about to commence its working movement. Fig. 2 is a side elevation of a conventional type of job press showing the combined safety and throw-off mechanism applied thereto, also showing the position of the parts when the movable work engaging element is at the end of its working movement, exerting or about to exert a pressure upon interposed work. Fig. 3 is a side elevation of a conventional type of job press showing the. combined safety and throw-off mechanism applied thereto, also showing the position of the parts thereof when the controller of the mechanism meets with resistance or is subjected to pressure, 2?. c. as shown in the drawing when the controller contacts with the fingers or any other part of the person of the operator. Fig. at is a rear elevation of Figs. 1, 2 and 3. Fig. 5 is a detail plan vview of the safety and throw-off mechanism showing it assembled. applied to the driving means and connected to the concentric reduced portion of the connecting shaft (shown in fragment) of tie movable work engaging element. Fig. 6 is a sectional view on the line A A of Fig. 1 showing the connection of one of the crank Hip pins of one disk to one of the driving links and the means of slidably mounting the projecting slotted central portion of the cam. Fig. 7-is a vertical section of Fig. 1 on the line 7 X showing the position of the com bined cam toggle link, one of the driving links being in contact with the shouldered portion thereof.

In the drawings reference numerals 1 and depict the frame of an ordinary job press, 3 the oscillating or movable work engaging element, l the oscillating platen, 5 the driving shaft having disks 6 and 7 mounted thereon. The disks carry the usual crank pins 8 and 9 to which one end of the driving links 10 and 11 is connected. The opposite ends of the links'are loosely journaled upon one-fend of the stud shafts 12 and 13.

Toggl links 1-1- are rigidly secured to tho projecting iids of the stud shafts l2 and 13 and are connected to and rigidly fitted to the reduced concentric stud portions 15 and 1(3 of the connecting cross shaft 17 of the movable work engaging element. The movable work engaging element is connected to the driving means in a manner which under normal conditions drives the movable work engaging element to the end of its working movement to act upon work interposed between the opposing elements but which, under certaiirabnormal conditions, is operable to prevent the movable work engaging element from completing its full working movement, thereby leaving a gap or safety zone between the elements.

The platen 1 is oscillated by the roller 18 which is rotatably mounted upon an arm 19. The arm is rigidly fitted to the platen shaft 20, and the roller engages and travels in the cam race 21, thereby automatically oscillating the platen when movement is imparted to the disks 6 and 7 and driving means.

The mechanism for connecting the driving links to the movable work engaging element are duplicates of each other except a part (preferably on the left side) of the press, comprising the unlocking member and the operating mechanism thereof is preferably dispensed with (as shown in the drawings), the means of connecting one link to the work engaging element therefore will only be described which is combined, arranged and constructed as follows:

:1 ca m 22 is provided on the toggle link 1+1 and a stud pin 23 is secured thereto projecting in a horizontal direction. An unlocking member 24 is provided with a slot 25 which is adapted to ht over and slidably engage the stud pin 23, thereby suspending one end of the unlocking member.

A. toe or foot portion 26 is preferably made integral with the unlocking member and carries rollers 27 and 28 which aline with and are adapted to contact with the face of the cam 22. Ear members 29 and 30 are also provided on the unlocking member 24 and they are apertured to provide journal bearings.

A cam plate 31 is provided having a centrally projecting slotted ofiset portion 32 which slidably engages the crank pin 8 and assists in supporting the cam plate. A boss 33 having a screw threaded aperture is provided on the cam plate and receives the screw-threaded end of a sliding rod 34'having a series of ratchet teeth 35 provided upon the upper portion thereof.

The rod 34 is adjustably connected to the boss of the cam plate by a nut 36. The free end of the rod 34 is slidably journaled in the bearing formed in the ears 29 and 30, thereby supporting the free end of the unlocking member 24 and incidentally assisting. in supporting the cam plate in conjunctiqn with the projecting portion 32 of t j cam-plateand crank pin 8. i f

An arm 37 is rigidly fastene in a predetermined position to the end of the crank pin 8 and its free end carries a roller 38 Which, as the arm is rotated by the crank pin carried by the disk, contacts with the cam face. An upwardly extending wing portion 39 is formed on the unlocking member and a bell crank pawl 4 is pivoted thereto by the slotted pin 41. The pawl is arranged directly over and in alinement with the ratchet teeth 35 of thesliding rod and the gravity thereof normally permits the end 42 of the pawl to engage the ratchet j teeth 35.

A horizontal projecting pin 43 is secured to the end of the crank portion 44 of the pawl bell crank and is alined with and lies in the path of the end 45 of an arm 46 which projects from a controller 47 that is pivotally mounted upon the cross connecting shaft 17 of the movable work engaging element. The controller has its free end 48 bent forwardly and preferably carries a roller 49 which depends between the opposing elements above the top of the bed but adjacent thereto, as shown in Fig. 4.

The operation and the application of the safety and throw-off mechanism to a job press of the type shown in its preferred construction, is as follows:

Referring now to Fig. 1, one end of each of the links 10 and 11 which carry the safety and throw-off mechanism is connected to the crank pins 8 and 9 and their opposite ends are loosely j ournaled upon the projecting end of the stud shafts 12 and 13 which shafts are rigidly connected to the links 14 and the links in turn are rigidly connected to the concentric stud portions of the shaft 17 When the bed, safety and throw-off mechanisms are in the position shown in Fig. 1, the bed is about to move toward the platen to the end of its working movement, and the combined cam toggle link 14 is normally held in locked position by the spring 50 which is attached to the link 11 011 one end, the opposite end being attached to a suitable portion of the link 14, the tension of the expansible spring 50 being such as to exert its tension to normally hold the axis of the concentric portion of the cross connecting shaft 17 upon a dead center position with the axis of the stud shaft as shown in Fig. 1, the shouldered portion 51 of the combined cam toggle link contacting with the lower edge of the link 11 when the dead center position of the link 14 is reached, thereby providing a dead center stop for the combined cam toggle link or links. \Vhen the press is operating normally, as shown in Figs. 1 and 2, the end 45 of the controlling arm 46 rests upon the pin 43 of the bell crank pawl and the gravity of the controller pivots the bell crank pawl upon the slotted pin 41 until it contacts with the stop pin 43 in which position the end 42 of the pawl is raised above the plane of and out of engagement with the series of ratchet teeth, or in other words, in inoperative position.

As the driving links reciprocate the work engaging element toward and from the oscillating platen under normal conditions to act upon the work interposed between the opposing element at the same time or simultaneously therewith, the arm 37 carrying the roller 38 is rotated around a circle and upon the forward or working movement of the movable work engaging element contacts with the cam plate race substantially between the points indicated by the reference letters a and Z), exerting a pressure thereupon and forcing the sliding ratchet rod 34 to slide in the bearings provided in the ears 29 and 30 to the position shown in Fig. 2. Upon the return or idle movement of the work engaging element, the arm 37 carrying the roller 38 forces said roller to contact with and travel over the are or ring portion 0 of the cam race of the cam plate, thereby returning the sliding ratchetrod 34 to the position shown in Fig. 1.

The above described operations take place continuously under normal conditions, the sliding ratchet rod and the movable work engaging element being reciprocated in unison under normal conditions. That is to say, when the controller is not obstructed subject to pressure or resistance.

If, however, as a pressure is exerted upon or the controller is resisted by an obstruction, as for instance the hand or any other part of the person of the operator should not be removed from between the elements, after feeding the work on the platen, in time to prevent the hand or any other part of the person from being caught between the pressure elements, then and in that event the controller will first come in contact with the hands or fingers of the person (or any other part of the person) and the controller will be forced to pivot and swing or rock upon its bearings on the cross connecting shaft 17, thereby raising or forcing the end 45 of the arm 46 of the controller from its contact with the pin 43 of the bell crank pawl (as shown in Fig. 3) and permitting the pawl to pivot and drop by gravity and its end %2 will then immediately engage with one of the series of ratchet teeth 35 exerting a pressure or push thereupon and rigidly connccting the unlocking member 24 to the sliding ratchet rod 34, at the same time the roller 38 of the arm 37 is exerting a pressure against the face of the cam plate between the points a and Z), the effect of which is to push or force the unlocking member forward and first cause the roller 27 to contact with the cam 22, then the roller 28 to contact with said cam 22 and finally the end wall of the slot 25 to further break the knee joint connection between the combined cam and toggle link or links and driving links, forcing them to assume the position shown in Fig. 3 which prevents the driving link from forcing the work engaging element to travel to the end of its working movement, thereby leaving a safety Zone or gap between the opposing elements.

VVhen the pressure or resistance on the controller is released or relieved, it swings back to its normal position, (as shown in Figs. 1 and 2) which brings the end 45 of the arm 46 in contact with the pin 43 forcing the bell crank pawl to pivot and the end thereof to be raised above the plane of the ratchet teeth and out of engagement therewith.

The engagement and disengagement of the end 45 of the bell crank pawl with the ratchet teeth for the purpose of pivotally connecting the combined safety and throwoff mechanisms for the purpose intended under abnormal conditions, and permitting it to remain in operative position under normal conditions, is accomplished automatically without in any way affecting the movement of the driving means or other mechanism except to govern or regulate the travel of the work engaging element toward the opposing element so as to leave a predetermined gap or safety zone between the op posing element when the controller meets resistance, an obstruction or is subjected to pressure as hereinbefore described.

As the complete safety and throw off mechanism, except the controller, is mounted upon the driving means, a self contained safety and throw-off mechanism is provided that can be applied to job presses now in use without alteration by simply taking ofi? the standard links and replacing them with the links to which the safety and throw -0fi mechanism is applied, as herein described, and mounting the controller upon a cross connecting shaft having reduced concentric portions.

Attention is further called to the fact that on account of the combined link cam toggles combining the link connection of the driving means to the movable work engaging element, the knee joint is broken instantly and simultaneously therewith, the bell crank pawl engages the ratchet sliding bar thereby immediately affording safety and stop ping the further movement of the work engaging element in the direction of the platen (until the obstruction of resistance is eliminated) leaving the safety gap or zone herein referred to or throw off the impression of the type at the will of the operator.

Attention is called to the fact that the reciprocation of the sliding ratchet rod is positive and continuous in both directions by reason of the form of the cam plate face and the constant contact therewith of the roller 28 of the arm 37 when the press is in operation. If desired, the stroke or movement of the sliding ratchet rod and consequently the gap between the elements can be varied by changing the dimensions of the arm 37, the form of the cam plate face, or by varying the form or number of teeth of the sliding ratchet bar.

Immaterial changes or alterations can be made in the structure and construction of the parts described without departing from the spirit of the invention herein described.

lVhat is claimed is:

1. In a combined safety and throw-off mechanism in combination with a movable work engaging element, driving means, means to connect the driving means to the movable work engaging element to normally force the work engaging element to travel to the end of its working movement, a connecting cross shaft, a controller pivotally mounted on said cross shaft, an unlocking member, means operable when the controller is subjected to pressure or resistance to actuate the unlocking member to prevent the driving means from driving the work engaging element to the end of its working movement.

2. In a combined safety and throw-off mechanism in combination with a movable work engaging element and an opposing element, comprising a driving means, a knee joint mechanism having a cam provided thereon to connect the driving means to the movable work engaging element to force it to travel to the end of its working move ment under normal conditions, a cross connecting shaft journaled on the work engaging element, a controller pivotally mounted iii/C upon the cross connecting shaft having its free end located between the elements, an unlocking member mounted on the driving means and adapted to contact with and exert a pressure upon the cam of the knee joint mechanism and means to permit the automatic actuation of the unlocking member to force the knee joint to break and thereby prevent the work engaging element from traveling to the end of its working movement when the controller is subjected to pressure or meets an obstruction.

3. In a combined safety and throw-off mechanism for machines having a movable work engaging element and an opposing element, driving means, links having cams provided thereon to connect the driving means to the work engaging element to form a knee joint therebetween, means to normally retain the knee joint connection on dead center for driving the movable work engaging element to the end of its working movement, a cross connecting shaft having concentric reduced portions on each end, a

controller pivotally mounted thereon, an unlocking member carrying rollers suspended onone end from the cam portion of the connecting links, a rod slidably connected at one end to the unlocking member, a disk carried by the driving means having a crank pin secured thereto, an arm carrying a roller fastened to the crank pin, a cam connected to the sliding rod surrounding said arm and adapted to be actuated thereby for reciprocating the sliding rod, and means mounted on the unlocking member operable to connect it to thesliding rod when the controller is resisted to force the unlocking member and roller carried thereby to break the knee joint connection and provide a safety zone between the opposing elements.

4:. In combination with a pair of work engaging elements adapted to operate upon work interposed therebetween, one of said elements being movable toward the other, driving means connected to the movable element to drive it in unison therewith and to permit independent movement thereof, an unlocking member movablv mounted on the driving means, means to automatically impart movement to the unlocking member to prevent the driving means from forcing the work engaging element to travel to the end of its working movement.

5 In combination with a pair of work engaging elements adapted to operate upon Work interposed therebetween, one of said elements being movable toward the other, driving means connected to the movable element to drive it in unison therewith and to permit independent movement thereof, an unlocking member movably mounted on the driving means, means to automatically operate the unlocking member to prevent the driving means from forcing the work engaging element to travel to the end of its working stroke comprising a ratchet rod slidably connected to the unlocking member on one end, means to prevent independent movement of the sliding ratchet rod and unlocking member, a cam connected to the opposite end of the sliding rod, a disk carrying a crank pin and an arm connected to the crank pin which is adapted to actuate the cam to impart a reciprocating movement to the sliding rod.

6. In combination with a pair of work engaging elements to operate upon work placed therebetween, one of said elements being movable toward the other, driving means, a knee joint member provided with a cam to connect one of the elements to the driving means, means to actuate the knee joint member to force themo-vable element to which it is connected to travel to the end of its working movement, across connecting shaft journaled to the movable element, a controller mounted on the cross connecting shaft, said cam and the knee joint meehanism being adapted to be automatically actuated by pressure upon the controller to prevent the movable element from being driven to the end of its Working movement, thereby leaving a safety zone between the elements to prevent injury to the person of the operator.

7. In a safety mechanism equipped with cooperating pressure elements, one being adapted to move toward the other, driving means yieldingly connected to the movable element, a movable unlocking member mounted on the driving means, a cam connected to the unlocking member, a disk carrying a crank pin, an arm secured to the crank pin which is adapted to impart movement to the cam and unlocking member, a controller pivotally mounted on the movable element to swing between the elements and adapted to automatically actuate the unlocking member to break the yielding connection when {subjected to pressure or resistance.

8. In a safety mechanism equipped with pressure applying members, one of said elements being movable toward the other, driving means yieldingly connected to the movable element and normally movably locked thereto to drive the movable element in unison therewith, an unlocking member mounted on the driving means, a controller mounted on the movable element, means to actuate the unlocking member to break the yielding connection between the driving means and movable element when the controller meets an obstruction thereby preventing the movable element from completing its work ing movement leaving a safety zone between the elements.

9. In a safety mechanism for machines equipped with pressure applying elements,

one of the elements being movable toward the other, driving moans yieldingly connected to the movable element and normally movably connected thereto to drive the movable element in unison therewith, an unlocking member mounted upon the driving means, a controller pivotally mounted upon the movable element, mechanism operable upon meeting an obstruction in its path extraneous to the work to automatically actuate the unlocking member to prevent the driving means from driving the movable element to the end of its working movement operable when the controller is resisted.

10. In a safety mechanism for machines equipped with pressure applying elements, one of the elements being movable toward the other, driving means yieldingly connected to the movable element and normally movably connected thereto to drive the movable element in unison therewith, an unlocking member mounted upon the driving means, a controller pivotally mounted upon the movable element, mechanism to automatically actuate the unlocking member to prevent the driving means from driving the movable element to the end of its working movement operable when the controller is resisted; said mechanism also being operable at the will of the operator by hand manipulation of the controller to prevent the movable element from completing its working movement, thereby preventing impression of the type on the w rk and at the same time leaving a safety gap between the elements.

11. In combination with a pair of work engaging elements adapted to operate upon work placed therebetween, driving means, knee joint means to yieldingly connect the driving means t0 one end of the elements for movement in unison under normal conditions, an unlocking member movably mounted on the driving means, supported on one end by the knee joint means, and adapt ed to co-act under abnormal conditions with the yielding connecting means to restrict and .revent the movement of the movable element in. unison with the driving means while being continuously connected thereto. 1'2. In a combined safety and throwo 'f mechanism for printing presses and analogous machines, in combination with cooperating pressure elements, means to reciprocate one of said elements to drive it to the end of its working movement under normal conditions, means to prevent the driving means from driving the reciprocating ele ment to the end of its working movement under abnormal conditions comprising a controller carried by the movable element, an unlocking member mounted on the driving means and mechanism automatically operable to actuate the unlocking means for the purpose intended when the controller is resisted or subjected to pressure by an obstruction extraneous to the work.

13. In a safety mechanism for machines equipped with cooperating pressure elements, driving links, links comprising a knee joint mechanism connecting one of the pressure elements to said driving links for reciprocation and to force it in juxtaposition with the opposing element under normal conditions, an unlocking member mounted on the driving means, a cam connected to the unlocking member for the actuation of same, a controller mounted on the reciproeating member, means to actuate the unlocking member by resistance upon the controller to prevent the driving means from forcing the movable element to complete its working stroke, thereby leaving a gap, between the elements.

14. In a safety mechanism for machines equipped with cooperating pressure elements, driving links, links comprising a knee joint mechanism connecting one of the pressure elements to said driving links for reciprocation and to force it in juxtaposition with the opposing element under normal conditions, an unlocking member mounted on the driving means, a cam connected to the unlocking member for the actuation of same, a controller mounted on the recipro' eating member, means to actuate the unlocking member by resistance upon the controller to prevent the driving means from forcing the movable element to complete its working stroke, thereby leaving a gap between the elements; said safety mechanism being operable automatically or by hand manipulation to perform the above described functions without affecting or stopping the movement of the driving means.

15. In a safety mechanism for machines equipped with pressure applying members, one of the members being movable toward the other, driving means, a knee joint mechanism having a cam pivoted thereon to con nect the driving means to the movable element for movement in unison and to permit idle movement with respect to the driving means, an unlocking member mounted upon the driving means and adapted to exert a pressure on said. cam, a controller mounted upon the movable element which is operable by an obstruction or resistance to actuate the unlocking member to break the knee joint mechanism and thereby prevent the movable element from completing its full working movement.

16. In a safety mechanism for machines equipped with pressure applying members, one of said members being movable toward the other, driving means, a knee oint mechanism to connect the driving means to the movable element for movement in unison and to permit idle movement with respect to the driving means, an unlocking member movably mounted on the driving means, a controller; said unlocking member being antomatioally, or by hand manipulation, operable by pressure upon the controller to regulate and govern the travel of the movable element to prevent the movable member from traveling to the end of its working movement.

17. In a safety mechanism for machines equipped with cooperative pressure elements, driving links, a knee joint mechanism combined with a cam to connect the driving links to one of the pressure members for reciprocation thereof to abut against the opposing element, an unlocking member, means to actuate the unlocking member to contact with the cam and force the knee joint mechanism on dead center position under normal conditions, acontroller mounted upon the movable element, and a cam plate and mechanismconnected thereto to actuate the unlocking member to break the knee oint connection between the driving links and movable element to prevent itfrom being driven to the end of its working movement when the controller is resisted.

18. In a safety mechanism for machines equipped with cooperating pressure members, driving means yieldingly connected to one of the members for reciprocation thereof, a controller pivotally mounted on the movable member with a portion thereof interposed between the elements, an unlocking member carried by the driving means, a ratchet rod slidably connected to said unlocking member to rigidly connect the unlocking member to the ratchet red, acam connected to the ratchet rod whereby the movable element is permitted to complete its working movement under normal conditions and stopped before it reaches the end of its working movement under abnormal conditions.

19. A combined safety and throw-0d mechanism for machines equipped with movable work engaging elements and an opposing element, driving means, links having cams connecting the driving means to the movable work engaging element forming a knee joint therebetween, mechanism carried by the driving means to operate on the cam throwing the connecting links 01? or on dead center position breaking the knee joint under abnormal conditions and maintaining the joint looked under normal conditions thereby restricting the travel of the movable elementtoward the opposing element to leave a gap .between them; said knee joint mechanism being cam actuated. as described and set forth.

20. A combined safety and throw-off mechanism for machines equipped with a movable work engaging element and an opposing element, driving means, links provided with cams connecting the driving means to the work engaging element forming a knee joint, mechanism carried by the driving means operating upon said cams to throw the connecting link off or on (lead center'position, breaking the knee joint under abnormal conditions and maintaining the joint looked under normal conditions thereby varying the distance traveled by the movable element to 'ard the opposing element for the purpose intended, a controller carried by the movable element, a. cam to actuate the safety mechanism carried by the driving means when the controller is resisted; said safety mechanism being otherwise inoperable.

21. In a combined safety and throw-oil mechanism for machines equipped with pressure applying members, one of the members being movable toward the other, a knee joint mechanism provided with cams to connect the driving means and movable element for movement in unison or independent of each other, a locking and unlocking means for the knee oint connection, a controller, means automatically operable by pressure upon the controller to unlock or break the knee joint connection by pres sure upon the cams of the knee joint connection;

22. In a combined safety and throw-oil mechanism for machines equipped with pressure applying members, one of the members being connected by yielding driving means for movement toward the other, a controller pivotally mounted on the movable member, combined safety and throw-oil mechanism carried by the driving means, a cam operatively connected to the combined safety and throw-01f mechanism to automatically operate same to prevent the movable member from traveling the complete distance toward the other, when said controller is resisted, and permitting the safety mechanism to remain inoperative when the controller is not resisted.

In testimony whereof I ailix my signature in presence of two witnesses.

CHARLES F. ROOT.

Witnesses PEARL M. YUNCHER, JOHN S. Boss.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents. Washington, D. G. 

